Math Help - Transformations

1. Transformations

Find the coordinates of the image point when (-4, -3) is rotated 1/4 turn ccw about (0, 0) and then reflected over the y axis.
ANy help is appreciated

2. The rotation matrix gives:
$\begin{gathered}
x' = x\cos (\theta ) - y\sin (\theta ) \hfill \\
y' = x\sin (\theta ) + y\cos (\theta ) \hfill \\
\end{gathered}$